Hi there, one of the lang designers here :)

Think of it this way. We already supported these semantics in existing syntax through things like invocations (which are freely allowed to mutate/write). So `x?.SetSomething(e1)`. We want properties to feel and behave similarly to methods (after all, they're just methods under the covers), but these sorts of deviations end up making that not the case.

In this situation, we felt like we were actually reducing concept count by removing yet another way that properties don't compose as well with other language features as something like invocation calls do.

Note: when we make these features we do do an examination of the ecosystem and we can see how useful the feature would be. We also are community continuously with our community and seeing just how desirable such a feature is. This goes beyond just those who participate on the open source design site. But also tons of private partners, as well as tens of thousands of developers participating at our conferences and other events.

This feature had been a continued thorn for many, and we received continuous feedback in the decade since `?.` was introduced about this. We are very cautious on adding features. But in this case, given the continued feedback, positive reception from huge swaths of the ecosystem, minimal costs, lowered complexity, and increased consistency in the language, this felt like a very reasonable change to make.

Thanks!